xref: /illumos-gate/usr/src/uts/i86pc/os/mp_startup.c (revision 44bf619d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 /*
26  * Copyright (c) 2010, Intel Corporation.
27  * All rights reserved.
28  */
29 /*
30  * Copyright 2019 Joyent, Inc.
31  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
32  * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/thread.h>
37 #include <sys/cpuvar.h>
38 #include <sys/cpu.h>
39 #include <sys/t_lock.h>
40 #include <sys/param.h>
41 #include <sys/proc.h>
42 #include <sys/disp.h>
43 #include <sys/class.h>
44 #include <sys/cmn_err.h>
45 #include <sys/debug.h>
46 #include <sys/note.h>
47 #include <sys/asm_linkage.h>
48 #include <sys/x_call.h>
49 #include <sys/systm.h>
50 #include <sys/var.h>
51 #include <sys/vtrace.h>
52 #include <vm/hat.h>
53 #include <vm/as.h>
54 #include <vm/seg_kmem.h>
55 #include <vm/seg_kp.h>
56 #include <sys/segments.h>
57 #include <sys/kmem.h>
58 #include <sys/stack.h>
59 #include <sys/smp_impldefs.h>
60 #include <sys/x86_archext.h>
61 #include <sys/machsystm.h>
62 #include <sys/traptrace.h>
63 #include <sys/clock.h>
64 #include <sys/cpc_impl.h>
65 #include <sys/pg.h>
66 #include <sys/cmt.h>
67 #include <sys/dtrace.h>
68 #include <sys/archsystm.h>
69 #include <sys/fp.h>
70 #include <sys/reboot.h>
71 #include <sys/kdi_machimpl.h>
72 #include <vm/hat_i86.h>
73 #include <vm/vm_dep.h>
74 #include <sys/memnode.h>
75 #include <sys/pci_cfgspace.h>
76 #include <sys/mach_mmu.h>
77 #include <sys/sysmacros.h>
78 #if defined(__xpv)
79 #include <sys/hypervisor.h>
80 #endif
81 #include <sys/cpu_module.h>
82 #include <sys/ontrap.h>
83 
84 struct cpu	cpus[1] __aligned(MMU_PAGESIZE);
85 struct cpu	*cpu[NCPU] = {&cpus[0]};
86 struct cpu	*cpu_free_list;
87 cpu_core_t	cpu_core[NCPU];
88 
89 #define	cpu_next_free	cpu_prev
90 
91 /*
92  * Useful for disabling MP bring-up on a MP capable system.
93  */
94 int use_mp = 1;
95 
96 /*
97  * to be set by a PSM to indicate what cpus
98  * are sitting around on the system.
99  */
100 cpuset_t mp_cpus;
101 
102 /*
103  * This variable is used by the hat layer to decide whether or not
104  * critical sections are needed to prevent race conditions.  For sun4m,
105  * this variable is set once enough MP initialization has been done in
106  * order to allow cross calls.
107  */
108 int flushes_require_xcalls;
109 
110 cpuset_t cpu_ready_set;		/* initialized in startup() */
111 
112 static void mp_startup_boot(void);
113 static void mp_startup_hotplug(void);
114 
115 static void cpu_sep_enable(void);
116 static void cpu_sep_disable(void);
117 static void cpu_asysc_enable(void);
118 static void cpu_asysc_disable(void);
119 
120 /*
121  * Init CPU info - get CPU type info for processor_info system call.
122  */
123 void
124 init_cpu_info(struct cpu *cp)
125 {
126 	processor_info_t *pi = &cp->cpu_type_info;
127 
128 	/*
129 	 * Get clock-frequency property for the CPU.
130 	 */
131 	pi->pi_clock = cpu_freq;
132 
133 	/*
134 	 * Current frequency in Hz.
135 	 */
136 	cp->cpu_curr_clock = cpu_freq_hz;
137 
138 	/*
139 	 * Supported frequencies.
140 	 */
141 	if (cp->cpu_supp_freqs == NULL) {
142 		cpu_set_supp_freqs(cp, NULL);
143 	}
144 
145 	(void) strcpy(pi->pi_processor_type, "i386");
146 	if (fpu_exists)
147 		(void) strcpy(pi->pi_fputypes, "i387 compatible");
148 
149 	cp->cpu_idstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
150 	cp->cpu_brandstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
151 
152 	/*
153 	 * If called for the BSP, cp is equal to current CPU.
154 	 * For non-BSPs, cpuid info of cp is not ready yet, so use cpuid info
155 	 * of current CPU as default values for cpu_idstr and cpu_brandstr.
156 	 * They will be corrected in mp_startup_common() after cpuid_pass1()
157 	 * has been invoked on target CPU.
158 	 */
159 	(void) cpuid_getidstr(CPU, cp->cpu_idstr, CPU_IDSTRLEN);
160 	(void) cpuid_getbrandstr(CPU, cp->cpu_brandstr, CPU_IDSTRLEN);
161 }
162 
163 /*
164  * Configure syscall support on this CPU.
165  */
166 /*ARGSUSED*/
167 void
168 init_cpu_syscall(struct cpu *cp)
169 {
170 	kpreempt_disable();
171 
172 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
173 	    is_x86_feature(x86_featureset, X86FSET_ASYSC)) {
174 		uint64_t flags;
175 
176 #if !defined(__xpv)
177 		/*
178 		 * The syscall instruction imposes a certain ordering on
179 		 * segment selectors, so we double-check that ordering
180 		 * here.
181 		 */
182 		CTASSERT(KDS_SEL == KCS_SEL + 8);
183 		CTASSERT(UDS_SEL == U32CS_SEL + 8);
184 		CTASSERT(UCS_SEL == U32CS_SEL + 16);
185 #endif
186 
187 		/*
188 		 * Turn syscall/sysret extensions on.
189 		 */
190 		cpu_asysc_enable();
191 
192 		/*
193 		 * Program the magic registers ..
194 		 */
195 		wrmsr(MSR_AMD_STAR,
196 		    ((uint64_t)(U32CS_SEL << 16 | KCS_SEL)) << 32);
197 		if (kpti_enable == 1) {
198 			wrmsr(MSR_AMD_LSTAR,
199 			    (uint64_t)(uintptr_t)tr_sys_syscall);
200 			wrmsr(MSR_AMD_CSTAR,
201 			    (uint64_t)(uintptr_t)tr_sys_syscall32);
202 		} else {
203 			wrmsr(MSR_AMD_LSTAR,
204 			    (uint64_t)(uintptr_t)sys_syscall);
205 			wrmsr(MSR_AMD_CSTAR,
206 			    (uint64_t)(uintptr_t)sys_syscall32);
207 		}
208 
209 		/*
210 		 * This list of flags is masked off the incoming
211 		 * %rfl when we enter the kernel.
212 		 */
213 		flags = PS_IE | PS_T;
214 		if (is_x86_feature(x86_featureset, X86FSET_SMAP) == B_TRUE)
215 			flags |= PS_ACHK;
216 		wrmsr(MSR_AMD_SFMASK, flags);
217 	}
218 
219 	/*
220 	 * On 64-bit kernels on Nocona machines, the 32-bit syscall
221 	 * variant isn't available to 32-bit applications, but sysenter is.
222 	 */
223 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
224 	    is_x86_feature(x86_featureset, X86FSET_SEP)) {
225 
226 #if !defined(__xpv)
227 		/*
228 		 * The sysenter instruction imposes a certain ordering on
229 		 * segment selectors, so we double-check that ordering
230 		 * here. See "sysenter" in Intel document 245471-012, "IA-32
231 		 * Intel Architecture Software Developer's Manual Volume 2:
232 		 * Instruction Set Reference"
233 		 */
234 		CTASSERT(KDS_SEL == KCS_SEL + 8);
235 
236 		CTASSERT(U32CS_SEL == ((KCS_SEL + 16) | 3));
237 		CTASSERT(UDS_SEL == U32CS_SEL + 8);
238 #endif
239 
240 		cpu_sep_enable();
241 
242 		/*
243 		 * resume() sets this value to the base of the threads stack
244 		 * via a context handler.
245 		 */
246 		wrmsr(MSR_INTC_SEP_ESP, 0);
247 
248 		if (kpti_enable == 1) {
249 			wrmsr(MSR_INTC_SEP_EIP,
250 			    (uint64_t)(uintptr_t)tr_sys_sysenter);
251 		} else {
252 			wrmsr(MSR_INTC_SEP_EIP,
253 			    (uint64_t)(uintptr_t)sys_sysenter);
254 		}
255 	}
256 
257 	kpreempt_enable();
258 }
259 
260 #if !defined(__xpv)
261 /*
262  * Configure per-cpu ID GDT
263  */
264 static void
265 init_cpu_id_gdt(struct cpu *cp)
266 {
267 	/* Write cpu_id into limit field of GDT for usermode retrieval */
268 #if defined(__amd64)
269 	set_usegd(&cp->cpu_gdt[GDT_CPUID], SDP_SHORT, NULL, cp->cpu_id,
270 	    SDT_MEMRODA, SEL_UPL, SDP_BYTES, SDP_OP32);
271 #elif defined(__i386)
272 	set_usegd(&cp->cpu_gdt[GDT_CPUID], NULL, cp->cpu_id, SDT_MEMRODA,
273 	    SEL_UPL, SDP_BYTES, SDP_OP32);
274 #endif
275 }
276 #endif /* !defined(__xpv) */
277 
278 /*
279  * Multiprocessor initialization.
280  *
281  * Allocate and initialize the cpu structure, TRAPTRACE buffer, and the
282  * startup and idle threads for the specified CPU.
283  * Parameter boot is true for boot time operations and is false for CPU
284  * DR operations.
285  */
286 static struct cpu *
287 mp_cpu_configure_common(int cpun, boolean_t boot)
288 {
289 	struct cpu *cp;
290 	kthread_id_t tp;
291 	caddr_t	sp;
292 	proc_t *procp;
293 #if !defined(__xpv)
294 	extern int idle_cpu_prefer_mwait;
295 	extern void cpu_idle_mwait();
296 #endif
297 	extern void idle();
298 	extern void cpu_idle();
299 
300 #ifdef TRAPTRACE
301 	trap_trace_ctl_t *ttc = &trap_trace_ctl[cpun];
302 #endif
303 
304 	ASSERT(MUTEX_HELD(&cpu_lock));
305 	ASSERT(cpun < NCPU && cpu[cpun] == NULL);
306 
307 	if (cpu_free_list == NULL) {
308 		cp = kmem_zalloc(sizeof (*cp), KM_SLEEP);
309 	} else {
310 		cp = cpu_free_list;
311 		cpu_free_list = cp->cpu_next_free;
312 	}
313 
314 	cp->cpu_m.mcpu_istamp = cpun << 16;
315 
316 	/* Create per CPU specific threads in the process p0. */
317 	procp = &p0;
318 
319 	/*
320 	 * Initialize the dispatcher first.
321 	 */
322 	disp_cpu_init(cp);
323 
324 	cpu_vm_data_init(cp);
325 
326 	/*
327 	 * Allocate and initialize the startup thread for this CPU.
328 	 * Interrupt and process switch stacks get allocated later
329 	 * when the CPU starts running.
330 	 */
331 	tp = thread_create(NULL, 0, NULL, NULL, 0, procp,
332 	    TS_STOPPED, maxclsyspri);
333 
334 	/*
335 	 * Set state to TS_ONPROC since this thread will start running
336 	 * as soon as the CPU comes online.
337 	 *
338 	 * All the other fields of the thread structure are setup by
339 	 * thread_create().
340 	 */
341 	THREAD_ONPROC(tp, cp);
342 	tp->t_preempt = 1;
343 	tp->t_bound_cpu = cp;
344 	tp->t_affinitycnt = 1;
345 	tp->t_cpu = cp;
346 	tp->t_disp_queue = cp->cpu_disp;
347 
348 	/*
349 	 * Setup thread to start in mp_startup_common.
350 	 */
351 	sp = tp->t_stk;
352 	tp->t_sp = (uintptr_t)(sp - MINFRAME);
353 #if defined(__amd64)
354 	tp->t_sp -= STACK_ENTRY_ALIGN;		/* fake a call */
355 #endif
356 	/*
357 	 * Setup thread start entry point for boot or hotplug.
358 	 */
359 	if (boot) {
360 		tp->t_pc = (uintptr_t)mp_startup_boot;
361 	} else {
362 		tp->t_pc = (uintptr_t)mp_startup_hotplug;
363 	}
364 
365 	cp->cpu_id = cpun;
366 	cp->cpu_self = cp;
367 	cp->cpu_thread = tp;
368 	cp->cpu_lwp = NULL;
369 	cp->cpu_dispthread = tp;
370 	cp->cpu_dispatch_pri = DISP_PRIO(tp);
371 
372 	/*
373 	 * cpu_base_spl must be set explicitly here to prevent any blocking
374 	 * operations in mp_startup_common from causing the spl of the cpu
375 	 * to drop to 0 (allowing device interrupts before we're ready) in
376 	 * resume().
377 	 * cpu_base_spl MUST remain at LOCK_LEVEL until the cpu is CPU_READY.
378 	 * As an extra bit of security on DEBUG kernels, this is enforced with
379 	 * an assertion in mp_startup_common() -- before cpu_base_spl is set
380 	 * to its proper value.
381 	 */
382 	cp->cpu_base_spl = ipltospl(LOCK_LEVEL);
383 
384 	/*
385 	 * Now, initialize per-CPU idle thread for this CPU.
386 	 */
387 	tp = thread_create(NULL, PAGESIZE, idle, NULL, 0, procp, TS_ONPROC, -1);
388 
389 	cp->cpu_idle_thread = tp;
390 
391 	tp->t_preempt = 1;
392 	tp->t_bound_cpu = cp;
393 	tp->t_affinitycnt = 1;
394 	tp->t_cpu = cp;
395 	tp->t_disp_queue = cp->cpu_disp;
396 
397 	/*
398 	 * Bootstrap the CPU's PG data
399 	 */
400 	pg_cpu_bootstrap(cp);
401 
402 	/*
403 	 * Perform CPC initialization on the new CPU.
404 	 */
405 	kcpc_hw_init(cp);
406 
407 	/*
408 	 * Allocate virtual addresses for cpu_caddr1 and cpu_caddr2
409 	 * for each CPU.
410 	 */
411 	setup_vaddr_for_ppcopy(cp);
412 
413 	/*
414 	 * Allocate page for new GDT and initialize from current GDT.
415 	 */
416 #if !defined(__lint)
417 	ASSERT((sizeof (*cp->cpu_gdt) * NGDT) <= PAGESIZE);
418 #endif
419 	cp->cpu_gdt = kmem_zalloc(PAGESIZE, KM_SLEEP);
420 	bcopy(CPU->cpu_gdt, cp->cpu_gdt, (sizeof (*cp->cpu_gdt) * NGDT));
421 
422 #if defined(__i386)
423 	/*
424 	 * setup kernel %gs.
425 	 */
426 	set_usegd(&cp->cpu_gdt[GDT_GS], cp, sizeof (struct cpu) -1, SDT_MEMRWA,
427 	    SEL_KPL, 0, 1);
428 #endif
429 
430 	/*
431 	 * Allocate pages for the CPU LDT.
432 	 */
433 	cp->cpu_m.mcpu_ldt = kmem_zalloc(LDT_CPU_SIZE, KM_SLEEP);
434 	cp->cpu_m.mcpu_ldt_len = 0;
435 
436 	/*
437 	 * Allocate a per-CPU IDT and initialize the new IDT to the currently
438 	 * runing CPU.
439 	 */
440 #if !defined(__lint)
441 	ASSERT((sizeof (*CPU->cpu_idt) * NIDT) <= PAGESIZE);
442 #endif
443 	cp->cpu_idt = kmem_alloc(PAGESIZE, KM_SLEEP);
444 	bcopy(CPU->cpu_idt, cp->cpu_idt, PAGESIZE);
445 
446 	/*
447 	 * alloc space for cpuid info
448 	 */
449 	cpuid_alloc_space(cp);
450 #if !defined(__xpv)
451 	if (is_x86_feature(x86_featureset, X86FSET_MWAIT) &&
452 	    idle_cpu_prefer_mwait) {
453 		cp->cpu_m.mcpu_mwait = cpuid_mwait_alloc(cp);
454 		cp->cpu_m.mcpu_idle_cpu = cpu_idle_mwait;
455 	} else
456 #endif
457 		cp->cpu_m.mcpu_idle_cpu = cpu_idle;
458 
459 	init_cpu_info(cp);
460 
461 #if !defined(__xpv)
462 	init_cpu_id_gdt(cp);
463 #endif
464 
465 	/*
466 	 * alloc space for ucode_info
467 	 */
468 	ucode_alloc_space(cp);
469 	xc_init_cpu(cp);
470 	hat_cpu_online(cp);
471 
472 #ifdef TRAPTRACE
473 	/*
474 	 * If this is a TRAPTRACE kernel, allocate TRAPTRACE buffers
475 	 */
476 	ttc->ttc_first = (uintptr_t)kmem_zalloc(trap_trace_bufsize, KM_SLEEP);
477 	ttc->ttc_next = ttc->ttc_first;
478 	ttc->ttc_limit = ttc->ttc_first + trap_trace_bufsize;
479 #endif
480 
481 	/*
482 	 * Record that we have another CPU.
483 	 */
484 	/*
485 	 * Initialize the interrupt threads for this CPU
486 	 */
487 	cpu_intr_alloc(cp, NINTR_THREADS);
488 
489 	cp->cpu_flags = CPU_OFFLINE | CPU_QUIESCED | CPU_POWEROFF;
490 	cpu_set_state(cp);
491 
492 	/*
493 	 * Add CPU to list of available CPUs.  It'll be on the active list
494 	 * after mp_startup_common().
495 	 */
496 	cpu_add_unit(cp);
497 
498 	return (cp);
499 }
500 
501 /*
502  * Undo what was done in mp_cpu_configure_common
503  */
504 static void
505 mp_cpu_unconfigure_common(struct cpu *cp, int error)
506 {
507 	ASSERT(MUTEX_HELD(&cpu_lock));
508 
509 	/*
510 	 * Remove the CPU from the list of available CPUs.
511 	 */
512 	cpu_del_unit(cp->cpu_id);
513 
514 	if (error == ETIMEDOUT) {
515 		/*
516 		 * The cpu was started, but never *seemed* to run any
517 		 * code in the kernel; it's probably off spinning in its
518 		 * own private world, though with potential references to
519 		 * our kmem-allocated IDTs and GDTs (for example).
520 		 *
521 		 * Worse still, it may actually wake up some time later,
522 		 * so rather than guess what it might or might not do, we
523 		 * leave the fundamental data structures intact.
524 		 */
525 		cp->cpu_flags = 0;
526 		return;
527 	}
528 
529 	/*
530 	 * At this point, the only threads bound to this CPU should
531 	 * special per-cpu threads: it's idle thread, it's pause threads,
532 	 * and it's interrupt threads.  Clean these up.
533 	 */
534 	cpu_destroy_bound_threads(cp);
535 	cp->cpu_idle_thread = NULL;
536 
537 	/*
538 	 * Free the interrupt stack.
539 	 */
540 	segkp_release(segkp,
541 	    cp->cpu_intr_stack - (INTR_STACK_SIZE - SA(MINFRAME)));
542 	cp->cpu_intr_stack = NULL;
543 
544 #ifdef TRAPTRACE
545 	/*
546 	 * Discard the trap trace buffer
547 	 */
548 	{
549 		trap_trace_ctl_t *ttc = &trap_trace_ctl[cp->cpu_id];
550 
551 		kmem_free((void *)ttc->ttc_first, trap_trace_bufsize);
552 		ttc->ttc_first = (uintptr_t)NULL;
553 	}
554 #endif
555 
556 	hat_cpu_offline(cp);
557 
558 	ucode_free_space(cp);
559 
560 	/* Free CPU ID string and brand string. */
561 	if (cp->cpu_idstr) {
562 		kmem_free(cp->cpu_idstr, CPU_IDSTRLEN);
563 		cp->cpu_idstr = NULL;
564 	}
565 	if (cp->cpu_brandstr) {
566 		kmem_free(cp->cpu_brandstr, CPU_IDSTRLEN);
567 		cp->cpu_brandstr = NULL;
568 	}
569 
570 #if !defined(__xpv)
571 	if (cp->cpu_m.mcpu_mwait != NULL) {
572 		cpuid_mwait_free(cp);
573 		cp->cpu_m.mcpu_mwait = NULL;
574 	}
575 #endif
576 	cpuid_free_space(cp);
577 
578 	if (cp->cpu_idt != CPU->cpu_idt)
579 		kmem_free(cp->cpu_idt, PAGESIZE);
580 	cp->cpu_idt = NULL;
581 
582 	kmem_free(cp->cpu_m.mcpu_ldt, LDT_CPU_SIZE);
583 	cp->cpu_m.mcpu_ldt = NULL;
584 	cp->cpu_m.mcpu_ldt_len = 0;
585 
586 	kmem_free(cp->cpu_gdt, PAGESIZE);
587 	cp->cpu_gdt = NULL;
588 
589 	if (cp->cpu_supp_freqs != NULL) {
590 		size_t len = strlen(cp->cpu_supp_freqs) + 1;
591 		kmem_free(cp->cpu_supp_freqs, len);
592 		cp->cpu_supp_freqs = NULL;
593 	}
594 
595 	teardown_vaddr_for_ppcopy(cp);
596 
597 	kcpc_hw_fini(cp);
598 
599 	cp->cpu_dispthread = NULL;
600 	cp->cpu_thread = NULL;	/* discarded by cpu_destroy_bound_threads() */
601 
602 	cpu_vm_data_destroy(cp);
603 
604 	xc_fini_cpu(cp);
605 	disp_cpu_fini(cp);
606 
607 	ASSERT(cp != CPU0);
608 	bzero(cp, sizeof (*cp));
609 	cp->cpu_next_free = cpu_free_list;
610 	cpu_free_list = cp;
611 }
612 
613 /*
614  * Apply workarounds for known errata, and warn about those that are absent.
615  *
616  * System vendors occasionally create configurations which contain different
617  * revisions of the CPUs that are almost but not exactly the same.  At the
618  * time of writing, this meant that their clock rates were the same, their
619  * feature sets were the same, but the required workaround were -not-
620  * necessarily the same.  So, this routine is invoked on -every- CPU soon
621  * after starting to make sure that the resulting system contains the most
622  * pessimal set of workarounds needed to cope with *any* of the CPUs in the
623  * system.
624  *
625  * workaround_errata is invoked early in mlsetup() for CPU 0, and in
626  * mp_startup_common() for all slave CPUs. Slaves process workaround_errata
627  * prior to acknowledging their readiness to the master, so this routine will
628  * never be executed by multiple CPUs in parallel, thus making updates to
629  * global data safe.
630  *
631  * These workarounds are based on Rev 3.57 of the Revision Guide for
632  * AMD Athlon(tm) 64 and AMD Opteron(tm) Processors, August 2005.
633  */
634 
635 #if defined(OPTERON_ERRATUM_88)
636 int opteron_erratum_88;		/* if non-zero -> at least one cpu has it */
637 #endif
638 
639 #if defined(OPTERON_ERRATUM_91)
640 int opteron_erratum_91;		/* if non-zero -> at least one cpu has it */
641 #endif
642 
643 #if defined(OPTERON_ERRATUM_93)
644 int opteron_erratum_93;		/* if non-zero -> at least one cpu has it */
645 #endif
646 
647 #if defined(OPTERON_ERRATUM_95)
648 int opteron_erratum_95;		/* if non-zero -> at least one cpu has it */
649 #endif
650 
651 #if defined(OPTERON_ERRATUM_100)
652 int opteron_erratum_100;	/* if non-zero -> at least one cpu has it */
653 #endif
654 
655 #if defined(OPTERON_ERRATUM_108)
656 int opteron_erratum_108;	/* if non-zero -> at least one cpu has it */
657 #endif
658 
659 #if defined(OPTERON_ERRATUM_109)
660 int opteron_erratum_109;	/* if non-zero -> at least one cpu has it */
661 #endif
662 
663 #if defined(OPTERON_ERRATUM_121)
664 int opteron_erratum_121;	/* if non-zero -> at least one cpu has it */
665 #endif
666 
667 #if defined(OPTERON_ERRATUM_122)
668 int opteron_erratum_122;	/* if non-zero -> at least one cpu has it */
669 #endif
670 
671 #if defined(OPTERON_ERRATUM_123)
672 int opteron_erratum_123;	/* if non-zero -> at least one cpu has it */
673 #endif
674 
675 #if defined(OPTERON_ERRATUM_131)
676 int opteron_erratum_131;	/* if non-zero -> at least one cpu has it */
677 #endif
678 
679 #if defined(OPTERON_WORKAROUND_6336786)
680 int opteron_workaround_6336786;	/* non-zero -> WA relevant and applied */
681 int opteron_workaround_6336786_UP = 0;	/* Not needed for UP */
682 #endif
683 
684 #if defined(OPTERON_WORKAROUND_6323525)
685 int opteron_workaround_6323525;	/* if non-zero -> at least one cpu has it */
686 #endif
687 
688 #if defined(OPTERON_ERRATUM_298)
689 int opteron_erratum_298;
690 #endif
691 
692 #if defined(OPTERON_ERRATUM_721)
693 int opteron_erratum_721;
694 #endif
695 
696 static void
697 workaround_warning(cpu_t *cp, uint_t erratum)
698 {
699 	cmn_err(CE_WARN, "cpu%d: no workaround for erratum %u",
700 	    cp->cpu_id, erratum);
701 }
702 
703 static void
704 workaround_applied(uint_t erratum)
705 {
706 	if (erratum > 1000000)
707 		cmn_err(CE_CONT, "?workaround applied for cpu issue #%d\n",
708 		    erratum);
709 	else
710 		cmn_err(CE_CONT, "?workaround applied for cpu erratum #%d\n",
711 		    erratum);
712 }
713 
714 static void
715 msr_warning(cpu_t *cp, const char *rw, uint_t msr, int error)
716 {
717 	cmn_err(CE_WARN, "cpu%d: couldn't %smsr 0x%x, error %d",
718 	    cp->cpu_id, rw, msr, error);
719 }
720 
721 /*
722  * Determine the number of nodes in a Hammer / Greyhound / Griffin family
723  * system.
724  */
725 static uint_t
726 opteron_get_nnodes(void)
727 {
728 	static uint_t nnodes = 0;
729 
730 	if (nnodes == 0) {
731 #ifdef	DEBUG
732 		uint_t family;
733 
734 		/*
735 		 * This routine uses a PCI config space based mechanism
736 		 * for retrieving the number of nodes in the system.
737 		 * Device 24, function 0, offset 0x60 as used here is not
738 		 * AMD processor architectural, and may not work on processor
739 		 * families other than those listed below.
740 		 *
741 		 * Callers of this routine must ensure that we're running on
742 		 * a processor which supports this mechanism.
743 		 * The assertion below is meant to catch calls on unsupported
744 		 * processors.
745 		 */
746 		family = cpuid_getfamily(CPU);
747 		ASSERT(family == 0xf || family == 0x10 || family == 0x11);
748 #endif	/* DEBUG */
749 
750 		/*
751 		 * Obtain the number of nodes in the system from
752 		 * bits [6:4] of the Node ID register on node 0.
753 		 *
754 		 * The actual node count is NodeID[6:4] + 1
755 		 *
756 		 * The Node ID register is accessed via function 0,
757 		 * offset 0x60. Node 0 is device 24.
758 		 */
759 		nnodes = ((pci_getl_func(0, 24, 0, 0x60) & 0x70) >> 4) + 1;
760 	}
761 	return (nnodes);
762 }
763 
764 uint_t
765 do_erratum_298(struct cpu *cpu)
766 {
767 	static int	osvwrc = -3;
768 	extern int	osvw_opteron_erratum(cpu_t *, uint_t);
769 
770 	/*
771 	 * L2 Eviction May Occur During Processor Operation To Set
772 	 * Accessed or Dirty Bit.
773 	 */
774 	if (osvwrc == -3) {
775 		osvwrc = osvw_opteron_erratum(cpu, 298);
776 	} else {
777 		/* osvw return codes should be consistent for all cpus */
778 		ASSERT(osvwrc == osvw_opteron_erratum(cpu, 298));
779 	}
780 
781 	switch (osvwrc) {
782 	case 0:		/* erratum is not present: do nothing */
783 		break;
784 	case 1:		/* erratum is present: BIOS workaround applied */
785 		/*
786 		 * check if workaround is actually in place and issue warning
787 		 * if not.
788 		 */
789 		if (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
790 		    ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0)) {
791 #if defined(OPTERON_ERRATUM_298)
792 			opteron_erratum_298++;
793 #else
794 			workaround_warning(cpu, 298);
795 			return (1);
796 #endif
797 		}
798 		break;
799 	case -1:	/* cannot determine via osvw: check cpuid */
800 		if ((cpuid_opteron_erratum(cpu, 298) > 0) &&
801 		    (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
802 		    ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0))) {
803 #if defined(OPTERON_ERRATUM_298)
804 			opteron_erratum_298++;
805 #else
806 			workaround_warning(cpu, 298);
807 			return (1);
808 #endif
809 		}
810 		break;
811 	}
812 	return (0);
813 }
814 
815 uint_t
816 workaround_errata(struct cpu *cpu)
817 {
818 	uint_t missing = 0;
819 
820 	ASSERT(cpu == CPU);
821 
822 	/*LINTED*/
823 	if (cpuid_opteron_erratum(cpu, 88) > 0) {
824 		/*
825 		 * SWAPGS May Fail To Read Correct GS Base
826 		 */
827 #if defined(OPTERON_ERRATUM_88)
828 		/*
829 		 * The workaround is an mfence in the relevant assembler code
830 		 */
831 		opteron_erratum_88++;
832 #else
833 		workaround_warning(cpu, 88);
834 		missing++;
835 #endif
836 	}
837 
838 	if (cpuid_opteron_erratum(cpu, 91) > 0) {
839 		/*
840 		 * Software Prefetches May Report A Page Fault
841 		 */
842 #if defined(OPTERON_ERRATUM_91)
843 		/*
844 		 * fix is in trap.c
845 		 */
846 		opteron_erratum_91++;
847 #else
848 		workaround_warning(cpu, 91);
849 		missing++;
850 #endif
851 	}
852 
853 	if (cpuid_opteron_erratum(cpu, 93) > 0) {
854 		/*
855 		 * RSM Auto-Halt Restart Returns to Incorrect RIP
856 		 */
857 #if defined(OPTERON_ERRATUM_93)
858 		/*
859 		 * fix is in trap.c
860 		 */
861 		opteron_erratum_93++;
862 #else
863 		workaround_warning(cpu, 93);
864 		missing++;
865 #endif
866 	}
867 
868 	/*LINTED*/
869 	if (cpuid_opteron_erratum(cpu, 95) > 0) {
870 		/*
871 		 * RET Instruction May Return to Incorrect EIP
872 		 */
873 #if defined(OPTERON_ERRATUM_95)
874 #if defined(_LP64)
875 		/*
876 		 * Workaround this by ensuring that 32-bit user code and
877 		 * 64-bit kernel code never occupy the same address
878 		 * range mod 4G.
879 		 */
880 		if (_userlimit32 > 0xc0000000ul)
881 			*(uintptr_t *)&_userlimit32 = 0xc0000000ul;
882 
883 		/*LINTED*/
884 		ASSERT((uint32_t)COREHEAP_BASE == 0xc0000000u);
885 		opteron_erratum_95++;
886 #endif	/* _LP64 */
887 #else
888 		workaround_warning(cpu, 95);
889 		missing++;
890 #endif
891 	}
892 
893 	if (cpuid_opteron_erratum(cpu, 100) > 0) {
894 		/*
895 		 * Compatibility Mode Branches Transfer to Illegal Address
896 		 */
897 #if defined(OPTERON_ERRATUM_100)
898 		/*
899 		 * fix is in trap.c
900 		 */
901 		opteron_erratum_100++;
902 #else
903 		workaround_warning(cpu, 100);
904 		missing++;
905 #endif
906 	}
907 
908 	/*LINTED*/
909 	if (cpuid_opteron_erratum(cpu, 108) > 0) {
910 		/*
911 		 * CPUID Instruction May Return Incorrect Model Number In
912 		 * Some Processors
913 		 */
914 #if defined(OPTERON_ERRATUM_108)
915 		/*
916 		 * (Our cpuid-handling code corrects the model number on
917 		 * those processors)
918 		 */
919 #else
920 		workaround_warning(cpu, 108);
921 		missing++;
922 #endif
923 	}
924 
925 	/*LINTED*/
926 	if (cpuid_opteron_erratum(cpu, 109) > 0) do {
927 		/*
928 		 * Certain Reverse REP MOVS May Produce Unpredictable Behavior
929 		 */
930 #if defined(OPTERON_ERRATUM_109)
931 		/*
932 		 * The "workaround" is to print a warning to upgrade the BIOS
933 		 */
934 		uint64_t value;
935 		const uint_t msr = MSR_AMD_PATCHLEVEL;
936 		int err;
937 
938 		if ((err = checked_rdmsr(msr, &value)) != 0) {
939 			msr_warning(cpu, "rd", msr, err);
940 			workaround_warning(cpu, 109);
941 			missing++;
942 		}
943 		if (value == 0)
944 			opteron_erratum_109++;
945 #else
946 		workaround_warning(cpu, 109);
947 		missing++;
948 #endif
949 	/*CONSTANTCONDITION*/
950 	} while (0);
951 
952 	/*LINTED*/
953 	if (cpuid_opteron_erratum(cpu, 121) > 0) {
954 		/*
955 		 * Sequential Execution Across Non_Canonical Boundary Caused
956 		 * Processor Hang
957 		 */
958 #if defined(OPTERON_ERRATUM_121)
959 #if defined(_LP64)
960 		/*
961 		 * Erratum 121 is only present in long (64 bit) mode.
962 		 * Workaround is to include the page immediately before the
963 		 * va hole to eliminate the possibility of system hangs due to
964 		 * sequential execution across the va hole boundary.
965 		 */
966 		if (opteron_erratum_121)
967 			opteron_erratum_121++;
968 		else {
969 			if (hole_start) {
970 				hole_start -= PAGESIZE;
971 			} else {
972 				/*
973 				 * hole_start not yet initialized by
974 				 * mmu_init. Initialize hole_start
975 				 * with value to be subtracted.
976 				 */
977 				hole_start = PAGESIZE;
978 			}
979 			opteron_erratum_121++;
980 		}
981 #endif	/* _LP64 */
982 #else
983 		workaround_warning(cpu, 121);
984 		missing++;
985 #endif
986 	}
987 
988 	/*LINTED*/
989 	if (cpuid_opteron_erratum(cpu, 122) > 0) do {
990 		/*
991 		 * TLB Flush Filter May Cause Coherency Problem in
992 		 * Multiprocessor Systems
993 		 */
994 #if defined(OPTERON_ERRATUM_122)
995 		uint64_t value;
996 		const uint_t msr = MSR_AMD_HWCR;
997 		int error;
998 
999 		/*
1000 		 * Erratum 122 is only present in MP configurations (multi-core
1001 		 * or multi-processor).
1002 		 */
1003 #if defined(__xpv)
1004 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
1005 			break;
1006 		if (!opteron_erratum_122 && xpv_nr_phys_cpus() == 1)
1007 			break;
1008 #else
1009 		if (!opteron_erratum_122 && opteron_get_nnodes() == 1 &&
1010 		    cpuid_get_ncpu_per_chip(cpu) == 1)
1011 			break;
1012 #endif
1013 		/* disable TLB Flush Filter */
1014 
1015 		if ((error = checked_rdmsr(msr, &value)) != 0) {
1016 			msr_warning(cpu, "rd", msr, error);
1017 			workaround_warning(cpu, 122);
1018 			missing++;
1019 		} else {
1020 			value |= (uint64_t)AMD_HWCR_FFDIS;
1021 			if ((error = checked_wrmsr(msr, value)) != 0) {
1022 				msr_warning(cpu, "wr", msr, error);
1023 				workaround_warning(cpu, 122);
1024 				missing++;
1025 			}
1026 		}
1027 		opteron_erratum_122++;
1028 #else
1029 		workaround_warning(cpu, 122);
1030 		missing++;
1031 #endif
1032 	/*CONSTANTCONDITION*/
1033 	} while (0);
1034 
1035 	/*LINTED*/
1036 	if (cpuid_opteron_erratum(cpu, 123) > 0) do {
1037 		/*
1038 		 * Bypassed Reads May Cause Data Corruption of System Hang in
1039 		 * Dual Core Processors
1040 		 */
1041 #if defined(OPTERON_ERRATUM_123)
1042 		uint64_t value;
1043 		const uint_t msr = MSR_AMD_PATCHLEVEL;
1044 		int err;
1045 
1046 		/*
1047 		 * Erratum 123 applies only to multi-core cpus.
1048 		 */
1049 		if (cpuid_get_ncpu_per_chip(cpu) < 2)
1050 			break;
1051 #if defined(__xpv)
1052 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
1053 			break;
1054 #endif
1055 		/*
1056 		 * The "workaround" is to print a warning to upgrade the BIOS
1057 		 */
1058 		if ((err = checked_rdmsr(msr, &value)) != 0) {
1059 			msr_warning(cpu, "rd", msr, err);
1060 			workaround_warning(cpu, 123);
1061 			missing++;
1062 		}
1063 		if (value == 0)
1064 			opteron_erratum_123++;
1065 #else
1066 		workaround_warning(cpu, 123);
1067 		missing++;
1068 
1069 #endif
1070 	/*CONSTANTCONDITION*/
1071 	} while (0);
1072 
1073 	/*LINTED*/
1074 	if (cpuid_opteron_erratum(cpu, 131) > 0) do {
1075 		/*
1076 		 * Multiprocessor Systems with Four or More Cores May Deadlock
1077 		 * Waiting for a Probe Response
1078 		 */
1079 #if defined(OPTERON_ERRATUM_131)
1080 		uint64_t nbcfg;
1081 		const uint_t msr = MSR_AMD_NB_CFG;
1082 		const uint64_t wabits =
1083 		    AMD_NB_CFG_SRQ_HEARTBEAT | AMD_NB_CFG_SRQ_SPR;
1084 		int error;
1085 
1086 		/*
1087 		 * Erratum 131 applies to any system with four or more cores.
1088 		 */
1089 		if (opteron_erratum_131)
1090 			break;
1091 #if defined(__xpv)
1092 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
1093 			break;
1094 		if (xpv_nr_phys_cpus() < 4)
1095 			break;
1096 #else
1097 		if (opteron_get_nnodes() * cpuid_get_ncpu_per_chip(cpu) < 4)
1098 			break;
1099 #endif
1100 		/*
1101 		 * Print a warning if neither of the workarounds for
1102 		 * erratum 131 is present.
1103 		 */
1104 		if ((error = checked_rdmsr(msr, &nbcfg)) != 0) {
1105 			msr_warning(cpu, "rd", msr, error);
1106 			workaround_warning(cpu, 131);
1107 			missing++;
1108 		} else if ((nbcfg & wabits) == 0) {
1109 			opteron_erratum_131++;
1110 		} else {
1111 			/* cannot have both workarounds set */
1112 			ASSERT((nbcfg & wabits) != wabits);
1113 		}
1114 #else
1115 		workaround_warning(cpu, 131);
1116 		missing++;
1117 #endif
1118 	/*CONSTANTCONDITION*/
1119 	} while (0);
1120 
1121 	/*
1122 	 * This isn't really an erratum, but for convenience the
1123 	 * detection/workaround code lives here and in cpuid_opteron_erratum.
1124 	 * Note, the technique only is valid on families before 12h and
1125 	 * certainly doesn't work when we're virtualized. This is checked for in
1126 	 * the erratum workaround.
1127 	 */
1128 	if (cpuid_opteron_erratum(cpu, 6336786) > 0) {
1129 #if defined(OPTERON_WORKAROUND_6336786)
1130 		/*
1131 		 * Disable C1-Clock ramping on multi-core/multi-processor
1132 		 * K8 platforms to guard against TSC drift.
1133 		 */
1134 		if (opteron_workaround_6336786) {
1135 			opteron_workaround_6336786++;
1136 #if defined(__xpv)
1137 		} else if ((DOMAIN_IS_INITDOMAIN(xen_info) &&
1138 		    xpv_nr_phys_cpus() > 1) ||
1139 		    opteron_workaround_6336786_UP) {
1140 			/*
1141 			 * XXPV	Hmm.  We can't walk the Northbridges on
1142 			 *	the hypervisor; so just complain and drive
1143 			 *	on.  This probably needs to be fixed in
1144 			 *	the hypervisor itself.
1145 			 */
1146 			opteron_workaround_6336786++;
1147 			workaround_warning(cpu, 6336786);
1148 #else	/* __xpv */
1149 		} else if ((opteron_get_nnodes() *
1150 		    cpuid_get_ncpu_per_chip(cpu) > 1) ||
1151 		    opteron_workaround_6336786_UP) {
1152 
1153 			uint_t	node, nnodes;
1154 			uint8_t data;
1155 
1156 			nnodes = opteron_get_nnodes();
1157 			for (node = 0; node < nnodes; node++) {
1158 				/*
1159 				 * Clear PMM7[1:0] (function 3, offset 0x87)
1160 				 * Northbridge device is the node id + 24.
1161 				 */
1162 				data = pci_getb_func(0, node + 24, 3, 0x87);
1163 				data &= 0xFC;
1164 				pci_putb_func(0, node + 24, 3, 0x87, data);
1165 			}
1166 			opteron_workaround_6336786++;
1167 #endif	/* __xpv */
1168 		}
1169 #else
1170 		workaround_warning(cpu, 6336786);
1171 		missing++;
1172 #endif
1173 	}
1174 
1175 	/*LINTED*/
1176 	/*
1177 	 * Mutex primitives don't work as expected. This is erratum #147 from
1178 	 * 'Revision Guide for AMD Athlon 64 and AMD Opteron Processors'
1179 	 * document 25759.
1180 	 */
1181 	if (cpuid_opteron_erratum(cpu, 6323525) > 0) {
1182 #if defined(OPTERON_WORKAROUND_6323525)
1183 		/*
1184 		 * This problem only occurs with 2 or more cores. If bit in
1185 		 * MSR_AMD_BU_CFG set, then not applicable. The workaround
1186 		 * is to patch the semaphone routines with the lfence
1187 		 * instruction to provide necessary load memory barrier with
1188 		 * possible subsequent read-modify-write ops.
1189 		 *
1190 		 * It is too early in boot to call the patch routine so
1191 		 * set erratum variable to be done in startup_end().
1192 		 */
1193 		if (opteron_workaround_6323525) {
1194 			opteron_workaround_6323525++;
1195 #if defined(__xpv)
1196 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2)) {
1197 			if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1198 				/*
1199 				 * XXPV	Use dom0_msr here when extended
1200 				 *	operations are supported?
1201 				 */
1202 				if (xpv_nr_phys_cpus() > 1)
1203 					opteron_workaround_6323525++;
1204 			} else {
1205 				/*
1206 				 * We have no way to tell how many physical
1207 				 * cpus there are, or even if this processor
1208 				 * has the problem, so enable the workaround
1209 				 * unconditionally (at some performance cost).
1210 				 */
1211 				opteron_workaround_6323525++;
1212 			}
1213 #else	/* __xpv */
1214 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2) &&
1215 		    ((opteron_get_nnodes() *
1216 		    cpuid_get_ncpu_per_chip(cpu)) > 1)) {
1217 			if ((xrdmsr(MSR_AMD_BU_CFG) & (UINT64_C(1) << 33)) == 0)
1218 				opteron_workaround_6323525++;
1219 #endif	/* __xpv */
1220 		}
1221 #else
1222 		workaround_warning(cpu, 6323525);
1223 		missing++;
1224 #endif
1225 	}
1226 
1227 	missing += do_erratum_298(cpu);
1228 
1229 	if (cpuid_opteron_erratum(cpu, 721) > 0) {
1230 #if defined(OPTERON_ERRATUM_721)
1231 		on_trap_data_t otd;
1232 
1233 		if (!on_trap(&otd, OT_DATA_ACCESS))
1234 			wrmsr(MSR_AMD_DE_CFG,
1235 			    rdmsr(MSR_AMD_DE_CFG) | AMD_DE_CFG_E721);
1236 		no_trap();
1237 
1238 		opteron_erratum_721++;
1239 #else
1240 		workaround_warning(cpu, 721);
1241 		missing++;
1242 #endif
1243 	}
1244 
1245 #ifdef __xpv
1246 	return (0);
1247 #else
1248 	return (missing);
1249 #endif
1250 }
1251 
1252 void
1253 workaround_errata_end()
1254 {
1255 #if defined(OPTERON_ERRATUM_88)
1256 	if (opteron_erratum_88)
1257 		workaround_applied(88);
1258 #endif
1259 #if defined(OPTERON_ERRATUM_91)
1260 	if (opteron_erratum_91)
1261 		workaround_applied(91);
1262 #endif
1263 #if defined(OPTERON_ERRATUM_93)
1264 	if (opteron_erratum_93)
1265 		workaround_applied(93);
1266 #endif
1267 #if defined(OPTERON_ERRATUM_95)
1268 	if (opteron_erratum_95)
1269 		workaround_applied(95);
1270 #endif
1271 #if defined(OPTERON_ERRATUM_100)
1272 	if (opteron_erratum_100)
1273 		workaround_applied(100);
1274 #endif
1275 #if defined(OPTERON_ERRATUM_108)
1276 	if (opteron_erratum_108)
1277 		workaround_applied(108);
1278 #endif
1279 #if defined(OPTERON_ERRATUM_109)
1280 	if (opteron_erratum_109) {
1281 		cmn_err(CE_WARN,
1282 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1283 		    " processor\nerratum 109 was not detected; updating your"
1284 		    " system's BIOS to a version\ncontaining this"
1285 		    " microcode patch is HIGHLY recommended or erroneous"
1286 		    " system\noperation may occur.\n");
1287 	}
1288 #endif
1289 #if defined(OPTERON_ERRATUM_121)
1290 	if (opteron_erratum_121)
1291 		workaround_applied(121);
1292 #endif
1293 #if defined(OPTERON_ERRATUM_122)
1294 	if (opteron_erratum_122)
1295 		workaround_applied(122);
1296 #endif
1297 #if defined(OPTERON_ERRATUM_123)
1298 	if (opteron_erratum_123) {
1299 		cmn_err(CE_WARN,
1300 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1301 		    " processor\nerratum 123 was not detected; updating your"
1302 		    " system's BIOS to a version\ncontaining this"
1303 		    " microcode patch is HIGHLY recommended or erroneous"
1304 		    " system\noperation may occur.\n");
1305 	}
1306 #endif
1307 #if defined(OPTERON_ERRATUM_131)
1308 	if (opteron_erratum_131) {
1309 		cmn_err(CE_WARN,
1310 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1311 		    " processor\nerratum 131 was not detected; updating your"
1312 		    " system's BIOS to a version\ncontaining this"
1313 		    " microcode patch is HIGHLY recommended or erroneous"
1314 		    " system\noperation may occur.\n");
1315 	}
1316 #endif
1317 #if defined(OPTERON_WORKAROUND_6336786)
1318 	if (opteron_workaround_6336786)
1319 		workaround_applied(6336786);
1320 #endif
1321 #if defined(OPTERON_WORKAROUND_6323525)
1322 	if (opteron_workaround_6323525)
1323 		workaround_applied(6323525);
1324 #endif
1325 #if defined(OPTERON_ERRATUM_298)
1326 	if (opteron_erratum_298) {
1327 		cmn_err(CE_WARN,
1328 		    "BIOS microcode patch for AMD 64/Opteron(tm)"
1329 		    " processor\nerratum 298 was not detected; updating your"
1330 		    " system's BIOS to a version\ncontaining this"
1331 		    " microcode patch is HIGHLY recommended or erroneous"
1332 		    " system\noperation may occur.\n");
1333 	}
1334 #endif
1335 #if defined(OPTERON_ERRATUM_721)
1336 	if (opteron_erratum_721)
1337 		workaround_applied(721);
1338 #endif
1339 }
1340 
1341 /*
1342  * The procset_slave and procset_master are used to synchronize
1343  * between the control CPU and the target CPU when starting CPUs.
1344  */
1345 static cpuset_t procset_slave, procset_master;
1346 
1347 static void
1348 mp_startup_wait(cpuset_t *sp, processorid_t cpuid)
1349 {
1350 	cpuset_t tempset;
1351 
1352 	for (tempset = *sp; !CPU_IN_SET(tempset, cpuid);
1353 	    tempset = *(volatile cpuset_t *)sp) {
1354 		SMT_PAUSE();
1355 	}
1356 	CPUSET_ATOMIC_DEL(*(cpuset_t *)sp, cpuid);
1357 }
1358 
1359 static void
1360 mp_startup_signal(cpuset_t *sp, processorid_t cpuid)
1361 {
1362 	cpuset_t tempset;
1363 
1364 	CPUSET_ATOMIC_ADD(*(cpuset_t *)sp, cpuid);
1365 	for (tempset = *sp; CPU_IN_SET(tempset, cpuid);
1366 	    tempset = *(volatile cpuset_t *)sp) {
1367 		SMT_PAUSE();
1368 	}
1369 }
1370 
1371 int
1372 mp_start_cpu_common(cpu_t *cp, boolean_t boot)
1373 {
1374 	_NOTE(ARGUNUSED(boot));
1375 
1376 	void *ctx;
1377 	int delays;
1378 	int error = 0;
1379 	cpuset_t tempset;
1380 	processorid_t cpuid;
1381 #ifndef __xpv
1382 	extern void cpupm_init(cpu_t *);
1383 #endif
1384 
1385 	ASSERT(cp != NULL);
1386 	cpuid = cp->cpu_id;
1387 	ctx = mach_cpucontext_alloc(cp);
1388 	if (ctx == NULL) {
1389 		cmn_err(CE_WARN,
1390 		    "cpu%d: failed to allocate context", cp->cpu_id);
1391 		return (EAGAIN);
1392 	}
1393 	error = mach_cpu_start(cp, ctx);
1394 	if (error != 0) {
1395 		cmn_err(CE_WARN,
1396 		    "cpu%d: failed to start, error %d", cp->cpu_id, error);
1397 		mach_cpucontext_free(cp, ctx, error);
1398 		return (error);
1399 	}
1400 
1401 	for (delays = 0, tempset = procset_slave; !CPU_IN_SET(tempset, cpuid);
1402 	    delays++) {
1403 		if (delays == 500) {
1404 			/*
1405 			 * After five seconds, things are probably looking
1406 			 * a bit bleak - explain the hang.
1407 			 */
1408 			cmn_err(CE_NOTE, "cpu%d: started, "
1409 			    "but not running in the kernel yet", cpuid);
1410 		} else if (delays > 2000) {
1411 			/*
1412 			 * We waited at least 20 seconds, bail ..
1413 			 */
1414 			error = ETIMEDOUT;
1415 			cmn_err(CE_WARN, "cpu%d: timed out", cpuid);
1416 			mach_cpucontext_free(cp, ctx, error);
1417 			return (error);
1418 		}
1419 
1420 		/*
1421 		 * wait at least 10ms, then check again..
1422 		 */
1423 		delay(USEC_TO_TICK_ROUNDUP(10000));
1424 		tempset = *((volatile cpuset_t *)&procset_slave);
1425 	}
1426 	CPUSET_ATOMIC_DEL(procset_slave, cpuid);
1427 
1428 	mach_cpucontext_free(cp, ctx, 0);
1429 
1430 #ifndef __xpv
1431 	if (tsc_gethrtime_enable)
1432 		tsc_sync_master(cpuid);
1433 #endif
1434 
1435 	if (dtrace_cpu_init != NULL) {
1436 		(*dtrace_cpu_init)(cpuid);
1437 	}
1438 
1439 	/*
1440 	 * During CPU DR operations, the cpu_lock is held by current
1441 	 * (the control) thread. We can't release the cpu_lock here
1442 	 * because that will break the CPU DR logic.
1443 	 * On the other hand, CPUPM and processor group initialization
1444 	 * routines need to access the cpu_lock. So we invoke those
1445 	 * routines here on behalf of mp_startup_common().
1446 	 *
1447 	 * CPUPM and processor group initialization routines depend
1448 	 * on the cpuid probing results. Wait for mp_startup_common()
1449 	 * to signal that cpuid probing is done.
1450 	 */
1451 	mp_startup_wait(&procset_slave, cpuid);
1452 #ifndef __xpv
1453 	cpupm_init(cp);
1454 #endif
1455 	(void) pg_cpu_init(cp, B_FALSE);
1456 	cpu_set_state(cp);
1457 	mp_startup_signal(&procset_master, cpuid);
1458 
1459 	return (0);
1460 }
1461 
1462 /*
1463  * Start a single cpu, assuming that the kernel context is available
1464  * to successfully start another cpu.
1465  *
1466  * (For example, real mode code is mapped into the right place
1467  * in memory and is ready to be run.)
1468  */
1469 int
1470 start_cpu(processorid_t who)
1471 {
1472 	cpu_t *cp;
1473 	int error = 0;
1474 	cpuset_t tempset;
1475 
1476 	ASSERT(who != 0);
1477 
1478 	/*
1479 	 * Check if there's at least a Mbyte of kmem available
1480 	 * before attempting to start the cpu.
1481 	 */
1482 	if (kmem_avail() < 1024 * 1024) {
1483 		/*
1484 		 * Kick off a reap in case that helps us with
1485 		 * later attempts ..
1486 		 */
1487 		kmem_reap();
1488 		return (ENOMEM);
1489 	}
1490 
1491 	/*
1492 	 * First configure cpu.
1493 	 */
1494 	cp = mp_cpu_configure_common(who, B_TRUE);
1495 	ASSERT(cp != NULL);
1496 
1497 	/*
1498 	 * Then start cpu.
1499 	 */
1500 	error = mp_start_cpu_common(cp, B_TRUE);
1501 	if (error != 0) {
1502 		mp_cpu_unconfigure_common(cp, error);
1503 		return (error);
1504 	}
1505 
1506 	mutex_exit(&cpu_lock);
1507 	tempset = cpu_ready_set;
1508 	while (!CPU_IN_SET(tempset, who)) {
1509 		drv_usecwait(1);
1510 		tempset = *((volatile cpuset_t *)&cpu_ready_set);
1511 	}
1512 	mutex_enter(&cpu_lock);
1513 
1514 	return (0);
1515 }
1516 
1517 void
1518 start_other_cpus(int cprboot)
1519 {
1520 	_NOTE(ARGUNUSED(cprboot));
1521 
1522 	uint_t who;
1523 	uint_t bootcpuid = 0;
1524 
1525 	/*
1526 	 * Initialize our own cpu_info.
1527 	 */
1528 	init_cpu_info(CPU);
1529 
1530 #if !defined(__xpv)
1531 	init_cpu_id_gdt(CPU);
1532 #endif
1533 
1534 	cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_idstr);
1535 	cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_brandstr);
1536 
1537 	/*
1538 	 * KPTI initialisation happens very early in boot, before logging is
1539 	 * set up. Output a status message now as the boot CPU comes online.
1540 	 */
1541 	cmn_err(CE_CONT, "?KPTI %s (PCID %s, INVPCID %s)\n",
1542 	    kpti_enable ? "enabled" : "disabled",
1543 	    x86_use_pcid == 1 ? "in use" :
1544 	    (is_x86_feature(x86_featureset, X86FSET_PCID) ? "disabled" :
1545 	    "not supported"),
1546 	    x86_use_pcid == 1 && x86_use_invpcid == 1 ? "in use" :
1547 	    (is_x86_feature(x86_featureset, X86FSET_INVPCID) ? "disabled" :
1548 	    "not supported"));
1549 
1550 	/*
1551 	 * Initialize our syscall handlers
1552 	 */
1553 	init_cpu_syscall(CPU);
1554 
1555 	/*
1556 	 * Take the boot cpu out of the mp_cpus set because we know
1557 	 * it's already running.  Add it to the cpu_ready_set for
1558 	 * precisely the same reason.
1559 	 */
1560 	CPUSET_DEL(mp_cpus, bootcpuid);
1561 	CPUSET_ADD(cpu_ready_set, bootcpuid);
1562 
1563 	/*
1564 	 * skip the rest of this if
1565 	 * . only 1 cpu dectected and system isn't hotplug-capable
1566 	 * . not using MP
1567 	 */
1568 	if ((CPUSET_ISNULL(mp_cpus) && plat_dr_support_cpu() == 0) ||
1569 	    use_mp == 0) {
1570 		if (use_mp == 0)
1571 			cmn_err(CE_CONT, "?***** Not in MP mode\n");
1572 		goto done;
1573 	}
1574 
1575 	/*
1576 	 * perform such initialization as is needed
1577 	 * to be able to take CPUs on- and off-line.
1578 	 */
1579 	cpu_pause_init();
1580 
1581 	xc_init_cpu(CPU);		/* initialize processor crosscalls */
1582 
1583 	if (mach_cpucontext_init() != 0)
1584 		goto done;
1585 
1586 	flushes_require_xcalls = 1;
1587 
1588 	/*
1589 	 * We lock our affinity to the master CPU to ensure that all slave CPUs
1590 	 * do their TSC syncs with the same CPU.
1591 	 */
1592 	affinity_set(CPU_CURRENT);
1593 
1594 	for (who = 0; who < NCPU; who++) {
1595 		if (!CPU_IN_SET(mp_cpus, who))
1596 			continue;
1597 		ASSERT(who != bootcpuid);
1598 
1599 		mutex_enter(&cpu_lock);
1600 		if (start_cpu(who) != 0)
1601 			CPUSET_DEL(mp_cpus, who);
1602 		cpu_state_change_notify(who, CPU_SETUP);
1603 		mutex_exit(&cpu_lock);
1604 	}
1605 
1606 	/* Free the space allocated to hold the microcode file */
1607 	ucode_cleanup();
1608 
1609 	affinity_clear();
1610 
1611 	mach_cpucontext_fini();
1612 
1613 done:
1614 	if (get_hwenv() == HW_NATIVE)
1615 		workaround_errata_end();
1616 	cmi_post_mpstartup();
1617 
1618 	if (use_mp && ncpus != boot_max_ncpus) {
1619 		cmn_err(CE_NOTE,
1620 		    "System detected %d cpus, but "
1621 		    "only %d cpu(s) were enabled during boot.",
1622 		    boot_max_ncpus, ncpus);
1623 		cmn_err(CE_NOTE,
1624 		    "Use \"boot-ncpus\" parameter to enable more CPU(s). "
1625 		    "See eeprom(1M).");
1626 	}
1627 }
1628 
1629 int
1630 mp_cpu_configure(int cpuid)
1631 {
1632 	cpu_t *cp;
1633 
1634 	if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1635 		return (ENOTSUP);
1636 	}
1637 
1638 	cp = cpu_get(cpuid);
1639 	if (cp != NULL) {
1640 		return (EALREADY);
1641 	}
1642 
1643 	/*
1644 	 * Check if there's at least a Mbyte of kmem available
1645 	 * before attempting to start the cpu.
1646 	 */
1647 	if (kmem_avail() < 1024 * 1024) {
1648 		/*
1649 		 * Kick off a reap in case that helps us with
1650 		 * later attempts ..
1651 		 */
1652 		kmem_reap();
1653 		return (ENOMEM);
1654 	}
1655 
1656 	cp = mp_cpu_configure_common(cpuid, B_FALSE);
1657 	ASSERT(cp != NULL && cpu_get(cpuid) == cp);
1658 
1659 	return (cp != NULL ? 0 : EAGAIN);
1660 }
1661 
1662 int
1663 mp_cpu_unconfigure(int cpuid)
1664 {
1665 	cpu_t *cp;
1666 
1667 	if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1668 		return (ENOTSUP);
1669 	} else if (cpuid < 0 || cpuid >= max_ncpus) {
1670 		return (EINVAL);
1671 	}
1672 
1673 	cp = cpu_get(cpuid);
1674 	if (cp == NULL) {
1675 		return (ENODEV);
1676 	}
1677 	mp_cpu_unconfigure_common(cp, 0);
1678 
1679 	return (0);
1680 }
1681 
1682 /*
1683  * Startup function for 'other' CPUs (besides boot cpu).
1684  * Called from real_mode_start.
1685  *
1686  * WARNING: until CPU_READY is set, mp_startup_common and routines called by
1687  * mp_startup_common should not call routines (e.g. kmem_free) that could call
1688  * hat_unload which requires CPU_READY to be set.
1689  */
1690 static void
1691 mp_startup_common(boolean_t boot)
1692 {
1693 	cpu_t *cp = CPU;
1694 	uchar_t new_x86_featureset[BT_SIZEOFMAP(NUM_X86_FEATURES)];
1695 	extern void cpu_event_init_cpu(cpu_t *);
1696 
1697 	/*
1698 	 * We need to get TSC on this proc synced (i.e., any delta
1699 	 * from cpu0 accounted for) as soon as we can, because many
1700 	 * many things use gethrtime/pc_gethrestime, including
1701 	 * interrupts, cmn_err, etc.  Before we can do that, we want to
1702 	 * clear TSC if we're on a buggy Sandy/Ivy Bridge CPU, so do that
1703 	 * right away.
1704 	 */
1705 	bzero(new_x86_featureset, BT_SIZEOFMAP(NUM_X86_FEATURES));
1706 	cpuid_pass1(cp, new_x86_featureset);
1707 
1708 	if (boot && get_hwenv() == HW_NATIVE &&
1709 	    cpuid_getvendor(CPU) == X86_VENDOR_Intel &&
1710 	    cpuid_getfamily(CPU) == 6 &&
1711 	    (cpuid_getmodel(CPU) == 0x2d || cpuid_getmodel(CPU) == 0x3e) &&
1712 	    is_x86_feature(new_x86_featureset, X86FSET_TSC)) {
1713 		(void) wrmsr(REG_TSC, 0UL);
1714 	}
1715 
1716 	/* Let the control CPU continue into tsc_sync_master() */
1717 	mp_startup_signal(&procset_slave, cp->cpu_id);
1718 
1719 #ifndef __xpv
1720 	if (tsc_gethrtime_enable)
1721 		tsc_sync_slave();
1722 #endif
1723 
1724 	/*
1725 	 * Once this was done from assembly, but it's safer here; if
1726 	 * it blocks, we need to be able to swtch() to and from, and
1727 	 * since we get here by calling t_pc, we need to do that call
1728 	 * before swtch() overwrites it.
1729 	 */
1730 	(void) (*ap_mlsetup)();
1731 
1732 #ifndef __xpv
1733 	/*
1734 	 * Program this cpu's PAT
1735 	 */
1736 	pat_sync();
1737 #endif
1738 
1739 	/*
1740 	 * Set up TSC_AUX to contain the cpuid for this processor
1741 	 * for the rdtscp instruction.
1742 	 */
1743 	if (is_x86_feature(x86_featureset, X86FSET_TSCP))
1744 		(void) wrmsr(MSR_AMD_TSCAUX, cp->cpu_id);
1745 
1746 	/*
1747 	 * Initialize this CPU's syscall handlers
1748 	 */
1749 	init_cpu_syscall(cp);
1750 
1751 	/*
1752 	 * Enable interrupts with spl set to LOCK_LEVEL. LOCK_LEVEL is the
1753 	 * highest level at which a routine is permitted to block on
1754 	 * an adaptive mutex (allows for cpu poke interrupt in case
1755 	 * the cpu is blocked on a mutex and halts). Setting LOCK_LEVEL blocks
1756 	 * device interrupts that may end up in the hat layer issuing cross
1757 	 * calls before CPU_READY is set.
1758 	 */
1759 	splx(ipltospl(LOCK_LEVEL));
1760 	sti();
1761 
1762 	/*
1763 	 * There exists a small subset of systems which expose differing
1764 	 * MWAIT/MONITOR support between CPUs.  If MWAIT support is absent from
1765 	 * the boot CPU, but is found on a later CPU, the system continues to
1766 	 * operate as if no MWAIT support is available.
1767 	 *
1768 	 * The reverse case, where MWAIT is available on the boot CPU but not
1769 	 * on a subsequently initialized CPU, is not presently allowed and will
1770 	 * result in a panic.
1771 	 */
1772 	if (is_x86_feature(x86_featureset, X86FSET_MWAIT) !=
1773 	    is_x86_feature(new_x86_featureset, X86FSET_MWAIT)) {
1774 		if (!is_x86_feature(x86_featureset, X86FSET_MWAIT)) {
1775 			remove_x86_feature(new_x86_featureset, X86FSET_MWAIT);
1776 		} else {
1777 			panic("unsupported mixed cpu mwait support detected");
1778 		}
1779 	}
1780 
1781 	/*
1782 	 * We could be more sophisticated here, and just mark the CPU
1783 	 * as "faulted" but at this point we'll opt for the easier
1784 	 * answer of dying horribly.  Provided the boot cpu is ok,
1785 	 * the system can be recovered by booting with use_mp set to zero.
1786 	 */
1787 	if (workaround_errata(cp) != 0)
1788 		panic("critical workaround(s) missing for cpu%d", cp->cpu_id);
1789 
1790 	/*
1791 	 * We can touch cpu_flags here without acquiring the cpu_lock here
1792 	 * because the cpu_lock is held by the control CPU which is running
1793 	 * mp_start_cpu_common().
1794 	 * Need to clear CPU_QUIESCED flag before calling any function which
1795 	 * may cause thread context switching, such as kmem_alloc() etc.
1796 	 * The idle thread checks for CPU_QUIESCED flag and loops for ever if
1797 	 * it's set. So the startup thread may have no chance to switch back
1798 	 * again if it's switched away with CPU_QUIESCED set.
1799 	 */
1800 	cp->cpu_flags &= ~(CPU_POWEROFF | CPU_QUIESCED);
1801 
1802 	enable_pcid();
1803 
1804 	/*
1805 	 * Setup this processor for XSAVE.
1806 	 */
1807 	if (fp_save_mech == FP_XSAVE) {
1808 		xsave_setup_msr(cp);
1809 	}
1810 
1811 	cpuid_pass2(cp);
1812 	cpuid_pass3(cp);
1813 	cpuid_pass4(cp, NULL);
1814 
1815 	/*
1816 	 * Correct cpu_idstr and cpu_brandstr on target CPU after
1817 	 * cpuid_pass1() is done.
1818 	 */
1819 	(void) cpuid_getidstr(cp, cp->cpu_idstr, CPU_IDSTRLEN);
1820 	(void) cpuid_getbrandstr(cp, cp->cpu_brandstr, CPU_IDSTRLEN);
1821 
1822 	cp->cpu_flags |= CPU_RUNNING | CPU_READY | CPU_EXISTS;
1823 
1824 	post_startup_cpu_fixups();
1825 
1826 	cpu_event_init_cpu(cp);
1827 
1828 	/*
1829 	 * Enable preemption here so that contention for any locks acquired
1830 	 * later in mp_startup_common may be preempted if the thread owning
1831 	 * those locks is continuously executing on other CPUs (for example,
1832 	 * this CPU must be preemptible to allow other CPUs to pause it during
1833 	 * their startup phases).  It's safe to enable preemption here because
1834 	 * the CPU state is pretty-much fully constructed.
1835 	 */
1836 	curthread->t_preempt = 0;
1837 
1838 	/* The base spl should still be at LOCK LEVEL here */
1839 	ASSERT(cp->cpu_base_spl == ipltospl(LOCK_LEVEL));
1840 	set_base_spl();		/* Restore the spl to its proper value */
1841 
1842 	pghw_physid_create(cp);
1843 	/*
1844 	 * Delegate initialization tasks, which need to access the cpu_lock,
1845 	 * to mp_start_cpu_common() because we can't acquire the cpu_lock here
1846 	 * during CPU DR operations.
1847 	 */
1848 	mp_startup_signal(&procset_slave, cp->cpu_id);
1849 	mp_startup_wait(&procset_master, cp->cpu_id);
1850 	pg_cmt_cpu_startup(cp);
1851 
1852 	if (boot) {
1853 		mutex_enter(&cpu_lock);
1854 		cp->cpu_flags &= ~CPU_OFFLINE;
1855 		cpu_enable_intr(cp);
1856 		cpu_add_active(cp);
1857 		mutex_exit(&cpu_lock);
1858 	}
1859 
1860 	/* Enable interrupts */
1861 	(void) spl0();
1862 
1863 	/*
1864 	 * Fill out cpu_ucode_info.  Update microcode if necessary.
1865 	 */
1866 	ucode_check(cp);
1867 	cpuid_pass_ucode(cp, new_x86_featureset);
1868 
1869 	/*
1870 	 * Do a sanity check to make sure this new CPU is a sane thing
1871 	 * to add to the collection of processors running this system.
1872 	 *
1873 	 * XXX	Clearly this needs to get more sophisticated, if x86
1874 	 * systems start to get built out of heterogenous CPUs; as is
1875 	 * likely to happen once the number of processors in a configuration
1876 	 * gets large enough.
1877 	 */
1878 	if (compare_x86_featureset(x86_featureset, new_x86_featureset) ==
1879 	    B_FALSE) {
1880 		cmn_err(CE_CONT, "cpu%d: featureset\n", cp->cpu_id);
1881 		print_x86_featureset(new_x86_featureset);
1882 		cmn_err(CE_WARN, "cpu%d feature mismatch", cp->cpu_id);
1883 	}
1884 
1885 #ifndef __xpv
1886 	{
1887 		/*
1888 		 * Set up the CPU module for this CPU.  This can't be done
1889 		 * before this CPU is made CPU_READY, because we may (in
1890 		 * heterogeneous systems) need to go load another CPU module.
1891 		 * The act of attempting to load a module may trigger a
1892 		 * cross-call, which will ASSERT unless this cpu is CPU_READY.
1893 		 */
1894 		cmi_hdl_t hdl;
1895 
1896 		if ((hdl = cmi_init(CMI_HDL_NATIVE, cmi_ntv_hwchipid(CPU),
1897 		    cmi_ntv_hwcoreid(CPU), cmi_ntv_hwstrandid(CPU))) != NULL) {
1898 			if (is_x86_feature(x86_featureset, X86FSET_MCA))
1899 				cmi_mca_init(hdl);
1900 			cp->cpu_m.mcpu_cmi_hdl = hdl;
1901 		}
1902 	}
1903 #endif /* __xpv */
1904 
1905 	if (boothowto & RB_DEBUG)
1906 		kdi_cpu_init();
1907 
1908 	(void) mach_cpu_create_device_node(cp, NULL);
1909 
1910 	/*
1911 	 * Setting the bit in cpu_ready_set must be the last operation in
1912 	 * processor initialization; the boot CPU will continue to boot once
1913 	 * it sees this bit set for all active CPUs.
1914 	 */
1915 	CPUSET_ATOMIC_ADD(cpu_ready_set, cp->cpu_id);
1916 
1917 	cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_idstr);
1918 	cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_brandstr);
1919 	cmn_err(CE_CONT, "?cpu%d initialization complete - online\n",
1920 	    cp->cpu_id);
1921 
1922 	/*
1923 	 * Now we are done with the startup thread, so free it up.
1924 	 */
1925 	thread_exit();
1926 	/*NOTREACHED*/
1927 }
1928 
1929 /*
1930  * Startup function for 'other' CPUs at boot time (besides boot cpu).
1931  */
1932 static void
1933 mp_startup_boot(void)
1934 {
1935 	mp_startup_common(B_TRUE);
1936 }
1937 
1938 /*
1939  * Startup function for hotplug CPUs at runtime.
1940  */
1941 void
1942 mp_startup_hotplug(void)
1943 {
1944 	mp_startup_common(B_FALSE);
1945 }
1946 
1947 /*
1948  * Start CPU on user request.
1949  */
1950 /* ARGSUSED */
1951 int
1952 mp_cpu_start(struct cpu *cp)
1953 {
1954 	ASSERT(MUTEX_HELD(&cpu_lock));
1955 	return (0);
1956 }
1957 
1958 /*
1959  * Stop CPU on user request.
1960  */
1961 int
1962 mp_cpu_stop(struct cpu *cp)
1963 {
1964 	extern int cbe_psm_timer_mode;
1965 	ASSERT(MUTEX_HELD(&cpu_lock));
1966 
1967 #ifdef __xpv
1968 	/*
1969 	 * We can't offline vcpu0.
1970 	 */
1971 	if (cp->cpu_id == 0)
1972 		return (EBUSY);
1973 #endif
1974 
1975 	/*
1976 	 * If TIMER_PERIODIC mode is used, CPU0 is the one running it;
1977 	 * can't stop it.  (This is true only for machines with no TSC.)
1978 	 */
1979 
1980 	if ((cbe_psm_timer_mode == TIMER_PERIODIC) && (cp->cpu_id == 0))
1981 		return (EBUSY);
1982 
1983 	return (0);
1984 }
1985 
1986 /*
1987  * Take the specified CPU out of participation in interrupts.
1988  *
1989  * Usually, we hold cpu_lock. But we cannot assert as such due to the
1990  * exception - i_cpr_save_context() - where we have mutual exclusion via a
1991  * separate mechanism.
1992  */
1993 int
1994 cpu_disable_intr(struct cpu *cp)
1995 {
1996 	if (psm_disable_intr(cp->cpu_id) != DDI_SUCCESS)
1997 		return (EBUSY);
1998 
1999 	cp->cpu_flags &= ~CPU_ENABLE;
2000 	ncpus_intr_enabled--;
2001 	return (0);
2002 }
2003 
2004 /*
2005  * Allow the specified CPU to participate in interrupts.
2006  */
2007 void
2008 cpu_enable_intr(struct cpu *cp)
2009 {
2010 	ASSERT(MUTEX_HELD(&cpu_lock));
2011 	cp->cpu_flags |= CPU_ENABLE;
2012 	ncpus_intr_enabled++;
2013 	psm_enable_intr(cp->cpu_id);
2014 }
2015 
2016 void
2017 mp_cpu_faulted_enter(struct cpu *cp)
2018 {
2019 #ifdef __xpv
2020 	_NOTE(ARGUNUSED(cp));
2021 #else
2022 	cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
2023 
2024 	if (hdl != NULL) {
2025 		cmi_hdl_hold(hdl);
2026 	} else {
2027 		hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
2028 		    cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
2029 	}
2030 	if (hdl != NULL) {
2031 		cmi_faulted_enter(hdl);
2032 		cmi_hdl_rele(hdl);
2033 	}
2034 #endif
2035 }
2036 
2037 void
2038 mp_cpu_faulted_exit(struct cpu *cp)
2039 {
2040 #ifdef __xpv
2041 	_NOTE(ARGUNUSED(cp));
2042 #else
2043 	cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
2044 
2045 	if (hdl != NULL) {
2046 		cmi_hdl_hold(hdl);
2047 	} else {
2048 		hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
2049 		    cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
2050 	}
2051 	if (hdl != NULL) {
2052 		cmi_faulted_exit(hdl);
2053 		cmi_hdl_rele(hdl);
2054 	}
2055 #endif
2056 }
2057 
2058 /*
2059  * The following two routines are used as context operators on threads belonging
2060  * to processes with a private LDT (see sysi86).  Due to the rarity of such
2061  * processes, these routines are currently written for best code readability and
2062  * organization rather than speed.  We could avoid checking x86_featureset at
2063  * every context switch by installing different context ops, depending on
2064  * x86_featureset, at LDT creation time -- one for each combination of fast
2065  * syscall features.
2066  */
2067 
2068 void
2069 cpu_fast_syscall_disable(void)
2070 {
2071 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2072 	    is_x86_feature(x86_featureset, X86FSET_SEP))
2073 		cpu_sep_disable();
2074 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2075 	    is_x86_feature(x86_featureset, X86FSET_ASYSC))
2076 		cpu_asysc_disable();
2077 }
2078 
2079 void
2080 cpu_fast_syscall_enable(void)
2081 {
2082 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2083 	    is_x86_feature(x86_featureset, X86FSET_SEP))
2084 		cpu_sep_enable();
2085 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2086 	    is_x86_feature(x86_featureset, X86FSET_ASYSC))
2087 		cpu_asysc_enable();
2088 }
2089 
2090 static void
2091 cpu_sep_enable(void)
2092 {
2093 	ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2094 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2095 
2096 	wrmsr(MSR_INTC_SEP_CS, (uint64_t)(uintptr_t)KCS_SEL);
2097 }
2098 
2099 static void
2100 cpu_sep_disable(void)
2101 {
2102 	ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2103 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2104 
2105 	/*
2106 	 * Setting the SYSENTER_CS_MSR register to 0 causes software executing
2107 	 * the sysenter or sysexit instruction to trigger a #gp fault.
2108 	 */
2109 	wrmsr(MSR_INTC_SEP_CS, 0);
2110 }
2111 
2112 static void
2113 cpu_asysc_enable(void)
2114 {
2115 	ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2116 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2117 
2118 	wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) |
2119 	    (uint64_t)(uintptr_t)AMD_EFER_SCE);
2120 }
2121 
2122 static void
2123 cpu_asysc_disable(void)
2124 {
2125 	ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2126 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2127 
2128 	/*
2129 	 * Turn off the SCE (syscall enable) bit in the EFER register. Software
2130 	 * executing syscall or sysret with this bit off will incur a #ud trap.
2131 	 */
2132 	wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) &
2133 	    ~((uint64_t)(uintptr_t)AMD_EFER_SCE));
2134 }
2135